Pitot heat power in most airliners I know of is controlled by way of
the squat switch (landing gear) to prevent burnout on the ground.

Javier


"Mike Rapoport" wrote in message thlink.net...
Leave it on all the time. Every checklist for a turbine airplane that I
have seen says to turn it on. All airlines leave it on all the time. Since
the heat is just a resistance element with no moving parts, I doubt that it
will "wear out faster" as others have suggested. Mine have 4600hrs on them
and presumably they have been on all that time.

Mike
MU-2


"K. Ari Krupnikov" wrote in message
...
Coming back from Mammoth this past Sunday and flying through a snow
cloud West of the Sierras, I had the Pitot freeze over. I realized it
was frozen when I tried to correct for altitude gained in turbulence
and the airspeed indication didn't increase even as I pushed the nose
down and could hear the relative wind increase. Not a big problem -- I
could see where I was going on the AI, and a minute or less after I
turned Pitot heat on, ASI returned to normal.

This did raise a question -- is there a good reason Pitot heat isn't
on all the time? It doesn't seem to be a big power drain, and unlike
carb heat does not to my knowledge affect performance. Is there a
reason I shouldn't turn it on when I put transponder on ALT and turn
it off when I shut down electrics before engine shutdown?

Ari.

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